10.
Distribution of Smiling Faces on FacebookHappy people cluster.Unhappy people cluster.SOCIAL NETWORKS AND HAPPINESS By Nicholas A. Christakis & James H. Fowler

11.
Experiences = More Happiness than ThingsLeaf van Boven and Thomas Gilovich. “To Do or to Have? That is the Question.” American Psychological Association. 85.6 (2003): 1198. Reprinted with permission.

12.
Distribution of Smiling Faces on FacebookHappy people cluster.Unhappy people cluster.SOCIAL NETWORKS AND HAPPINESS By Nicholas A. Christakis & James H. Fowler

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Achievement: mastering skills. Csikszentmihalyi has created the theory of Flow to explain why people are happy when they’re applying skills that they’re good at. Evolutionary explanations for positive psychology are emerging.